Four people were killed in the Boulder County plane crash that sparked a wildfire Sunday, according to the Federal Aviation Administration. The Cessna P337 went down under unknown circumstances in Boulder, the FAA said in a report on the agency’s website. The aircraft was listed as “destroyed,” with one member of the flight crew and three passengers killed. The victims’ identities have not yet been publicly released. The plane, built in 1972, was registered to Broomfield-based VX Aviation LLC, according to FAA records.